New socket off a single socket connected to a 6amp RCD

[atoone1977]

Hi,

I have a separate consumer unit feeding utility, garden, outbuildings, garage etc. However, there is just a single socket in the garage which is used for the electric garage door. This seems to be a single spur off a 6amp RCD on the consumer unit.

I want to add a new double socket in the garage so would i be ok running this from the single socket, even though its only 6amp? Any advice is muchly appreciated, thanks!

 

[JohnD]

It's not an RCD.

6A is suitable for a lighting circuit, not for a socket.

Show us some photos.

 

[Taylortwocities]

Is the consumer unit in the garage, by any chance?

 

[ericmark]

What we need to know is why you have a 6A MCB. There are loads of reasons, from the electrician only having a 6A in his collection when he fitted it, to using a lighting circuit, to the cable being only rated 6A, to door needing max 6A supply. To know if it can be upgraded we need all the information, it should be on the installation certificate. If you don't have the installation certificate it will need testing and the test equipment is too expensive to be in a DIY tool kit.

Pictures may help, plus cable sizes, and info on the door.

 

[atoone1977]

...

 

[atoone1977]

Thanks for the quick replies guys!

The consumer unit is in the utility, next to the garage. The cable looks to me to be 2.5mm twin + earth, but thats just my guess. Here's some pics. Its the 'Car Port' we're looking at at am pretty sure its just this one single socket connected.

20151209_104148

• atoone1977
• 9 Dec 2015

20151209_104914

• atoone1977
• 9 Dec 2015

 

[atoone1977]

Just done a bit more reading and i now know this is an MCB and not an RCD But any advice is going to be helpful!

 

[Taylortwocities]

A guide to cable sizes is in the WIKI at //www.diynot.com/wiki/Electrics:flatpvccables
In this, it will tell you the approximate outside dimensions of typical cables. From this you may be able to determine the size of the cable feeding the socket.
With any luck, it will be 2.5mm².
Then we will need to look inside the consumer unit and check that there is only one cable coming from that MCB.
Then we need to check if that socket circuit is RCD protected. (A pic of the inside of the CU will help).

If all of the above is true, the next thing to do would be to add another socket from the existing (using 2.5mm² cable) and get a bigger MCB (maximum 20amp) to replace the 6amp one. Unless you are used to messing around inside consumer units, I would recommend you get an electrician in to do this.

Just as a PS. WHat would you be planning to plug into the new socket? If its just a string of Christmas lights, then 6amp will be plenty…..

 

[atoone1977]

Thanks. There's only one cable coming out of the mcb (3rd from left) and the cable is definitely 2.5mm. Would it just be a case of swapping out the 6amp MCB with a 20amp one then i'm free to go? The new sockets will only be used occasionally for a leaf blower, pressure washer or strimmer.

p.s I've isolated this feed from the main CU and checked all was dead before i fiddled around with it

 

[Taylortwocities]

Thanks. There's only one cable coming out of the mcb (3rd from left) and the cable is definitely 2.5mm. Would it just be a case of swapping out the 6amp MCB with a 20amp one then i'm free to go? p.s I've isolated this feed from the main CU and checked all was dead before i fiddled around with it

I am not convinced that it is 2.5mm². The two cables in the B32 MCB will be 2.5mm². The ones in the B6 MCBS in positions 2 and 3 appear to be smaller. They may only be 1.5mm².

From the pic I would judge the conductor sizes to be

Position
1 - 4mm²
2 - 2.5mm²
3 - 1.5mm²
4 - 1.5mm²
5 - 2.5mm²

What makes you so sure the cable definitely is 2.5mm² ??

Also, I do not see an RCD in the picture, is it to the right of the B32 MCB?



EDIT You said the Car Port MCB is

(3rd from left)

Don't you mean second from the left???

 

[atoone1977]

You are quite right, it's second left!! Sorry for the confusion. I've checked and double checked am convinced its 2.5mm. Here's a full picture of the CU, witht the RCD on the right.

 

[Taylortwocities]

OK, in that case get a replacement 20A Hager mcb and swop it, then u can add the additional socket.

 

[atoone1977]

Ok, i'll give it a go! Thanks for your help and perseverance!!

 

[kai]

Do make sure that it is actually a HAGER breaker that you buy for that unit - don't try to shove another manufacturer's breaker into the space.